veltum



R. E. VELTUM.

PNEUMATIC TOOL.

' APPLICATION FILED OCT. 24. 1914 y: I 1 19mm, PatentedAug. 1,1916.

51 mm Mm; f? I wm (git/J? m wwwag R. E. VELTUM.

PNEUMATIC TOOL.

APPLICATION HLED OCT. 24. 1914.

ii. 11 $55 331 & Patented'AugE 1, 1916.

1 2 SHEETS-SHEET 2. flfilyz'yn ROBERT E. VELTUM. OF EUGENE, OREGON.

PNEUMATIC TODL.

lawman Specification of Letters Patent.

Paienied Zin i 391 6.

Application filed Dctober 24. 1914. Seria No. 868,460.

iie it known thal I. Rom-arr idoi'iciircxi. a eitizen of {he initedStates. residing in Eugene. in the county of Lane and State of Oregon.have invented certain new and useful improvements in lneuiuatie Tools.ol which "ihe following is a speeilieation.

The oh ieet of this invention is to furnish an improved portahle lool.operahle hy compressed air or other fluid under pressure. whereh anoscillating molion ol' the working? head is produced. so that themachine is suiiiahle for grinding Yal\'e operating a rat het drill. orother purposes requiring a rapid {wand-fro moti n. For aeconiplishingihis oli ieii two areuale oi'liuders are pro- \ided. with a piston ineaeh. hoth pistons being connected io a common driving sha'l'i; andoppositely arranged. so that when one piston isat' one end o'l' itsstroke the other is at the other end of its stroke. wherehy impulses inopposite directions are given alternately to ihe shal't. A. suital le\alvcmechanism controls the lluid supply so as to produce. the reversalof movement of the pistons at the proper limes.

in the aei'ronipanyinir drawings. Figure 1 is an eici'ation ola nap-hincemhodying the invention. hie. L is a top view of Fig. 1, Fig. 2% is a\ertieal central section through the machine ol Fig. l. on a iarereeaie. Fig. --l is a top View of one of ihe ineinhcrs of he machine inwhich one of the ey'linilers is partly formed. Fig. 5 is an elevation ofthe. ihiringr shaft and the pistons connected therewith. Fig. 3 is a topriew oi" the pisstons. sha'l't and eonneeling rods. Fig. 7 is a side.View of a part of the vali'ceontrolling devices. Fig. 2 is a vie at aright angle to Fig. 7. Figs. 1) and it) are details of the valve. hie.1U heing a section on line i0-10 of Fig. 1). ulh'. Figs. ll and 12 aredetails of one of the pistons.

Similar reference characters indieale the same parts throughout thefigures.

Referring to the drawings. the main-hioek 1!) ol' the tool has thereintwo areuate grooves .l l. 12. one at the front face and one at the rearface of the same. The frontplatc 13 has at its rear face a correspondinggroove 14'. and the rear-phite 153 has a C(iTl'Qf-lpUDdlIlg gro ve .16.,said grooves forming when the )laies are secured in. place on the main--hlo k. areuatc channels of cylindrical cross secilm, each extendingnearly the full cirhloek.

Jsoi' like curved form and extends in the cylinder 2-3 in like manner, adistance greater eu miierenee of a circle. as shown in Fig. 4. Screws4;! of which one is shown. secure tho plates and main-hloek together.

drivingshalt 17 is journaled at its inner end in a socket in in therear-plate l5, and extends through a central opening 32 in the hloek land is journaled in a hearing i in the front-plate 13. it extendsi'orwardl heyond the front-phite and at its outer end is provided with a('lumpingI-soeliei it having. a screw 21. wherelr'v an desired worktop]can he secured to the shall.

In the front eylinder '12 is located a piston 33. and in the rearcylinder QB-i is located a piston 23. Caeh piston eomprises a head iii.a eupshaped washer liof leather or other suilahle material. and anexpansion spring. 28 within the eup-shaped washer. The head 213 issecured at the end ol a connecting rod which extends forward heyond theh ad and is sere\\'-threaileil and receives a nut 21) by "which thepiston washer 27 is retained in place against the h *ad. The eonneelingrod :10 of the. piston extends therefrom in the cylinder 24 for a greaer distance than the length of the stroke of the piston. and is thenhent at an angle and connected at its inner end with the shaft 17. Inorder to reach said shaft. the rod passes through a siot 31 which isformed between the main hloek it) and the rear plate 15 h cutting: awa)a portion of the metal of each hetween the cylinder 16 an'd the centralopening 32 of the main The connecting rod 35 of piston 23 thantheclengjth of the stroke of the. piston. and then extends inwardlythrough a slot 33 to the driving shaft 17. The two pistons arcoppositely disposed, that is to say, they are oppositely directed intheir respective cylinders and so located that when one is at one end ofits stroke, the other is at the other end of its stroke- The air supplyduct 36 is located in the rear plate 15 and connects with acorrcsponding duct- 37 in the main block 10, which communicates with avalve-chest 38 in said main block. From said valve-chest 38 extends aduct 35) to the cylinder 22, and a duct U. to the cylinder 24*. A mainexhaust, channel 42) extends from the valve-chest to the outside of theblock. In the valvcchcst is located a valve i of circular form, andhaving a recess 45 in which is located a finger 46 which is secured tothe end of a valve stem ,47. The valve stem extends in the main block tothe central opening a .the same, and is there provided with a knuckle 48having an antifriction roller 49 located in the path of two pins 50, 51,respectively, which extend radially from and are spaced apart upon theshaft 17. The valve is provided with a port 52 adapted to place thevalve-chest 38 in communication with one of the supply ducts to one ofthe cylinders, and with a port 53 adapted to place said valve-chest incommunication with the supply duct for the other cylinder, and with aduct 54 for making, the proper connection of either of said air-supplyduets with the main exhaust duct 43,.the ducts 39 and 41 servinalternately for inlet and exhaust. A plate 05 closes the valve-chest 38at the outside of the main block. A fiat spring 56 between said plateand the valve retains the valve properly seated in the valve-chest, andgives suilicient friction so that it holds whatever positoin it may begiven by the finger 46. The valve is provided at itsperiphery with arecess 72. An abutment projects from the main block ll) into said recessand limits the movement of the valve in either direction. A pawl isprovided for properly locating the knuckle at each time that the latteris thrown by one of the pins 50.51, and for assisting; in the movementof the knuckle and valve. Said pawl comprises a main member 57 slidingin an opening in the rear plate 15 and guided therein by aslot and pin58, and carrying at its knuckleengaging end an antil riction roller 5%).A

compression-spring 60 bears inwardly upon the member 5 and is itselfcapable of adjustment as to pressure by an adjusting screw (31 havingits head exposed at the utside'of the rear plate. A throttle-valv (i2 isprovided on the rearplate 1:), whereby the supply of air passing throughthe duct 36 .may be readily controlled. A handle (14 extends rearwardlyfrom the rear plate and is provided with a duct communicating, with theduct 36. A swivelconnection ($6 at the rear end of the handle permitsthe attachment of the hose 67 by which the compressed air or othermotive fluid may be supplied to the machine.

in Fig. 1, the valve isshown in median position. In operation, the valvebeing for example atone end of its motion. the port 53 is in registerwith the supply duct ilSHmd permits air to flow from the valve-chest 38to cylinder 22, and move the piston 23 in driving direction therein. Atthe same time piston 25 is being moved on its return stroke in cylinder24, and the air in front of the same is escaping through duct 41,exhaust duct 5- of the valve, and exhaust. duct 43 .in the main-block10, to the atmosphere.

Motion of the pistons and of the drivingshaft continues until pin 51strikes roller 4Q. of the valve-tripping device, and moves the knuckle48 so that the high point 70 of the same passes under the roller 59. Thepawl then by pressure on the knuckle, throws it quickly to the limit ofits movement and retains itthere. During the first part of the knucklemovement, when itis impelled by the pin 51, the finger l6 plays of themachine by the adjustin -screw (31.

In the new position of the valve, port 52 is'in register with duct 41leading to cylinder 24, whereby air is permitted to pass from thevalve-chest to the cylinder 24 and drive the piston forward. At the sametime exhaust escapes from cylinder 22 through duct 39, valve-duct 54 andexhaust duct 43 to the atmosphere. Near the end of the stroke, pin 50engages roller 49 of the valve-tripping device, and the valve is tgainthrown in the manner before described, but in opposite direction, intothe position first assumed. The admission of air alternately to bothcylinders, and exhaustion of the same therefrom, and the resulting rapidmotion of the pistons and driving-shaft, first in one direction and thenin the other continues until the supply of air or other driving-fluid iscut oil. The speed of the tool may be reduced whenever desired byscrewing down the throttle-yalve (52, whereby the air-supply duct 36 ispartially closed, or may be inv creased from a low speed to full speedby but is not limited to these uses, and may be employed for any and allpurposes requiring that the working tool be given a rapid oscillatingmotion.

The invention is not limited to the particular structure described, butchanges "may be madev thereinwithout departing from the spirit of theinvention as set forth in the appended claims.

I claim: l c

l. A portable motor comprising a main block having two arcuatecylinders, oppositely disposed pistons within said cylinders, so thatwhen one is at one end of its work- ,haust duct.

chest adapted to be oscillated, and provided with inlet ports adapted toalternately register with the said inlet ducts, and an exhaust portadapted to alternately register with said ducts and said exhaust port,and means for oscillating the said valve. 2. A portable motor comprisinga main block, having two arcuate cylinders, oppositely disposedpistonswithin said cylinders, so thatwhen oneis at one end of itsworking stroke, the other .is at the opposite end of its working stroke,a shaft adapted to be oscillated by the working of said pistons, andradial projections on the said shaft, a valve chest on'said main block,means for supplyingair to said valve chest, d lcts from said valve "hestto said arcuate cylinders adapted to alternately supply and exhaust airinto and out of said cylinders, an exa valve within said chest adaptedto be oscillated and provided with inlet ports adapted to alternatelyregister with said inlet ducts to supply air to the cylinders, anexhaust port adapted to register with said ducts and said exhaust ductto exhaust air from the said cylinders, and a valve-sten1 adapted to bealternately enon the main block,

block leading to the gaged by the projections of the said oscillatingshaft, to oscillate the said valve.

3. A portable motor comprising a main block having a central opening, afront plate and a rear plate, a shaft in said opening journaled in saidfront plate and rear plate, meansadapted to be alternately operated tooscillate the said shaft, an air valve mounted to oscillate on the mainblock, and having a stem extending to the central opening of the saidmain block, a valve tripping (lento vice in said opening adaptedtooscillate said valve-stein, an air-supply duct in the main said valve,ducts from the valve to-the said means for oscillating the shaft, anexhaust passage from the valve to the outside of the main block, meanson the rear plate for regulating the supply of air through theair-supply duct therein, a

handle extending rearwardly from the rear plate, and having an airconduit connecting with the air-supply duct of the rear plate, a swivelhose coupling at the end of the handle, a tool clamp on the exposed endof the shaft, and detachable means securing said main block, front plateand rearplate together in operative alinement.

In testimony that I claim the foregoing as my invention, I'have signedmy name in presence of two subscribing witnesses.

ROBERT E. VELTUM.

\Vitnesses:

Louis E. BEAN, 'AnLoNE ROCKWELL.

